1. Field of the Invention
The present invention relates to a shock absorber, and more particularly, to a shock absorber which is capable of preventing mutual collision of internal parts by using a damping force through a movement of a fluid when excessive shock is transferred.
2. Description of the Related Art
Generally, a shock absorber is designed to suppress or reduce a vibration from a road surface. The shock absorber is mounted between a vehicle body or frame and a wheel, and absorbs vertical vibration energy of a vehicle body to thereby suppress a vibration and improve a ride comfort.
In addition, the shock absorber can increase a durability life by reducing dynamic stress of each part of a vehicle body, ensure a ground characteristic of a tire by suppressing a motion of unsprung mass, and improve motion performance of a vehicle by suppressing a posture change due to an inertial force.
The shock absorber includes a cylinder with an inner tube and an outer tube, a piston valve reciprocating within the inner tube, a piston rod having one end connected to the piston valve and the other end located outside the cylinder, and a body valve installed at an end of the cylinder to face the piston valve.
In addition, the shock absorber includes a stopper on an outer periphery of the piston rod so as to prevent collision between the piston valve and a rod guide due to a rebound of the piston rod when great shock is applied to the vehicle.
Examples of the conventional stopper include a rubber elastic body or a coil-type rebound spring, which is installed between the rod guide and the piston valve to apply an elastic compression force.
However, in the case where the coil-type spring is used as the stopper, the volume of the apparatus is increased and there is a difficulty in design due to the stroke of the stopper. When the total length is increased, the coil-type stopper inevitably generates noise due to the occurrence of buckling, and a separate guide needs to be applied for supporting both ends of the spring, which makes the configuration complicated.
In relation to the present invention, a damper is disclosed in Korean Patent Application Publication No. 10-2011-0047974 (published on May 9, 2011).